This invention is directed to a precursor for iron oxide paint pigment composed of metallic cores found in scarfer spittings, a steel mill waste material.
Scarfer spittings are a steel mill waste material produced by scarfing steel blooms, slabs and billets prior to or during processing to remove surface defects. Scarfing consists of rapidly removing the surface of steel by the use of a fuel containing oxygen applied to the surface by means of a torch or torches. The oxygen oxidizes a portion of the steel thereby generating heat and increasing the temperature to cause the steel to become molten. The partially oxidized generally globular product thus formed is referred to as scarfer spittings. The scarfer spittings are cooled and flushed from the surface of the steel by high pressure water and are collected in a water bath. The scarfer spittings range in size from smaller than 0.149 mm to larger than 50.8 mm in diameter and are generally comprised of an outer brittle shell composed substantially of iron oxides and an inner metallic core.
At the present time scarfer spittings have no specific use other than recycling in the steel mill to recover the iron which they contain. A portion of the spittings are mixed with mill scale, steel borings and the like and are used as part of the charge to a sinter strand to recover the iron. However, only the larger sized particles or spittings can be so used. In recent years, increased emphasis on the surface cleanliness of steel has resulted in an increase in the use of automatic scarfing machines to scarf the steel surfaces. As a result, the volume of scarfer spittings produced in a steel mill has increased, thereby increasing the time required to transport the spittings and the amount of storage space required for the spittings. There is, therefore, a need to find an economical use for the scarfer spittings.
It is the object of this invention to provide an iron oxide paint pigment precursor comprised of metallic cores recoverd from a steel mill waste product, i.e. scarfer spittings, produced during the scarfing of steel.